﻿/*
 * 扩展方法
 */

var a = "123";
bool b = a.IsNullOrEmpty();
var c = a.Append("456").Append("789");

public static class StringExtensions
{
    public static bool IsNullOrEmpty(this string value)
    {
        return !string.IsNullOrWhiteSpace(value);
    }

    public static string Append(this string value, string text)
    {
        return value + text;
    }
}